640604 has 12 divisors (see below), whose sum is σ = 1180200. Its totient is φ = 303408.

The previous prime is 640589. The next prime is 640613. The reversal of 640604 is 406046.

640604 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 640604.

It is an unprimeable number.

640604 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4139 + ... + 4290.

It is an arithmetic number, because the mean of its divisors is an integer number (98350).

2⁶⁴⁰⁶⁰⁴ is an apocalyptic number.

It is an amenable number.

640604 is a deficient number, since it is larger than the sum of its proper divisors (539596).

640604 is a wasteful number, since it uses less digits than its factorization.

640604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8452 (or 8450 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 640604 is about 800.3774109756. The cubic root of 640604 is about 86.2044890472.

The spelling of 640604 in words is "six hundred forty thousand, six hundred four".